Appliance Performance in the Field: Refrigerators

@Efficiency for Access

Until recently, solar-powered refrigerators had been used primarily by health centers in off- and weak-grid areas to preserve vaccines. Due to the technology improvements and cost reduction of solar photovoltaic (PV) panels, batteries and refrigeration units themselves, standalone solar-powered refrigerators have started to penetrate the household and productive use of renewable energy (PURE) markets. Many entrepreneurs and SME owners are now starting to use solar-powered refrigerators to sell cold beverages as a way to generate additional income and to improve their livelihoods.

Off-grid refrigerators remain fairly nascent and have had limited uptake by consumers to date – less than 3,000 off-grid refrigerators from affiliated manufacturers were sold in the first half of 2022, which is significantly lower compared to other appliances such as fans, televisions, radios or solar water pumps. Therefore, user feedback can be highly beneficial for manufacturers and distributors to understand the needs and expectations from end-users. For programmes like Low Energy Inclusive Appliances (LEIA), where one of its activities is focused on designing test methods and quality standards, the user insights are valuable to improve performance measurements so that the results are reflective of the real field conditions. Performance and user insights from field testing are also valuable when it comes to improving design, identifying use cases, estimating impact on income, evaluating after-sales services and reflecting on user awareness needs to allow for smooth operations.

The field testing was conducted in Rwanda and India to evaluate the impact of use cases and user behaviour on refrigerator performance. The performance data was complemented by user feedback gathered via baseline and end-line surveys of more than 40 participants. The aim of the report is to provide user-centric insight for refrigerator manufacturers, distributors and other stakeholders engaged in the cooling sector.

Some key observations

  • Most users used refrigerators for productive use, which enabled them to increase income and offer fresh produce and cooled products to their customers. 90% of users across both countries used refrigerators to generate additional income by selling fresh produce and cold beverages. The income associated with the use of refrigerators varied significantly per user, country, and season.
  • Refrigerator performance was heavily influenced by user behaviour. More than one third of users in Rwanda turned their refrigerators off every night which negatively impacted the internal compartment temperature and power consumption when turned back on. We observed similar situation in India, where some users turned their refrigerators off for even longer periods. This was related to the fact that 85% users in India and 32% users in Rwanda reported that they do not know how to operate the refrigerator to reduce power consumption. Therefore, they may have turned the refrigerators off assuming that it will reduce power consumption, although the refrigerators are designed to provide consistent cooling at night and during cloudy days by using the incorporated battery and thermal storage.
  • The overall user satisfaction was relatively high although improvements related to performance, training and after-sales services are still required. Most users across both countries indicated that they would recommend the refrigerator to a friend with a score of 6/10 or above (95% in Rwanda and 79% in India). Furthermore, nine users in Rwanda reported the highest possible score when it comes to recommending the refrigerator to their friend compared to only one user in India. Users with low satisfaction rate complained about refrigerator performance, poor training, and inadequate after-sales services when it comes to repair.
  • Field testing data collection is challenging, especially when it comes to performance monitoring. Survey data collection was relatively straightforward. The main challenge was related to the user availability, which resulted in a small sample of interviews were baseline and endline surveys were completed by different respondents (e.g. shop owner versus family member or shop employee). Remote performance data monitoring was significantly more challenging. All the door opening sensors (apart from one in each country) became loose soon after installation, four SD cards were malfunctional and the real-time data platform was not working. Having said that, we were able to retrieve and analyse performance data for the remaining refrigerators (apart from the ones that were being repaired, not being used by the users for prolonged periods, or sensors being removed and not reinstalled by the users).
  • Direct comparison of field testing results with laboratory results is challenging due to the variety of ambient temperatures, user behaviour and products stored. One of the aims of the research was to compare field testing data with VeraSol. 23 Refrigerators tested under VeraSol operate in controlled ambient temperatures and humidity, without door openings and with empty internal compartments. However, none of these parameters can be controlled in the field. We collected ambient temperature and humidity data but we lacked door opening data (frequency and duration) and products being stored in the refrigerator at the given time including type, quantity and temperature when entering the refrigerator.


Excerpt of: Evaluating Appliance Performance in the Field: Results from Refrigerator Testing (Efficiency for Access Coalition 2023)


Download the full report here.